4, 4, 6-trimethyl-2-thio-tetrahydro-1, 3, 2-oxazine



Patented Aug. 10, 1943 1 ED; were-E 1 4,4,6:minuErHYLa-rHIorTE'rRAHYDBoraz-oxAzmu Barry L. Fisher, Stamford, i 001111., assignor to U. S. Industi-ialAlcohol Co.,.New York, N. corporation of West Virginia Nbpm ing. Application May 7,1941,

- Serial No. 392,346

2 Claims.

This invention relates to anew organic compound, to the method of preparing it, and to its practical application, especially as an accelerator of vulcanization of rubber. This new organic 'substancehas various? advantageous uses inthe rubber and otherindustries. 7 -.It.is theobject of the invention to provide a new and-useful organic compound, .a: practical method of preparing it and an economical and I satisfactory application of the compound in the vulcanization of rubber.

Other objects and advantages of the invention will be apparent as it is better understood by reference to the following specification, in which the preferred embodiments of the invention are described.

The invention pertains particularly to 4,4,6 trimethyl-2-thio-tetrahydro-1,3,2-oxazine which is the product of the reaction of diacetonalkamine (4-aminoA-methyl-Zmentanol) and carbon disulfide.

The reaction probably takes with the following equation:

place in accordance CH3 CH3 CH2 CH3.0.GH2-CH.C H3+CS2 KOH C CILCHs-I-HzS NHr OH /HN 0 A typical example of a method of preparation of the substance is as follows:

Sixteen grams of potassium hydroxide are dissolved in 200 cc. of absolute alcohol, and 98 grams of diacetonalkamine laz nino-e-methyl-2-pentanol) and 88 cc. of carbon disulfide slowly added with stirring. After this mixture has stood for about 1 hour, it is heated under reflux for 7-8 hours on the steambath. During this heating hydrogen sulfide gas'is evolved, and crystals of the product form in the mixture. The mixture is allowed to cool to room temperature. The crystals are then filtered 01f and washed with a small The yield of the oxazine amount of cold water. is 125 grams, which is 94% of the theoretical amount. The melting point of the crude product is 208 C., and after recrystallization 210-11 0;, uncorrected.

The substance is soluble in hot glacial acetic acid and hot acetone; lightly soluble in cold glacial acetic acid, acetone and dioxane; and. practically insoluble in alcohol, water and aqueous alkalies. V

Analysis of-the purified substance gave the following results:

Calculated r r for Found C7H1aONS Carbon" 79 0 Hydrogen Nitrogen- V SulIur I 20.13 20. 00 Molecular weight (by Rasts method)..." 159. 24 152 From these results it appears that the reaction goes as indicated above and that the structural formula of the substance is correct as given.

The oxazine shows marked action as an accelerator of vulcanization. 1 Below isgiven a comparison of the action offithe oxazine and a well, known commercial accelerator, mercaptobenzothiazole, popularly called Captax, in. a tread stock and a white molded stock. In'the tread stock it is seen that although their molecular j I weights are close together, namely 159 and 167,

1 part of the oxazine is as potent as 1.5 parts of Captax. It is also useful in latex'compounds. Y

The tests were on unaged stocks. The cures are given in the number of minutes at the desig nated pounds per square inch of steam pressure;

T represents the tensile strength in pounds per square inch and E the per cent elongation, both i 

